Boiler construction



Oct. 11, 1932. F. J. CURRAN 1,882,319

' BOILER CONSTRUCTION Original F iled March 15. 1927 a w a v MM 1 0/0 mI I Ir h a E i 9 2 mmmm llll ll T 7/M// 4/ ////////7//A w w 8 a W 2 1Patented Oct. 1 1, 1932 Y UNITED STATES imam: I. own

mm, or new Yonx, N. mnssrenon, mam'nsm: A'ssIema srmn rownmmc, Aconclusion or nnnawaan PATIENT OFFICE EN'IQTO BOILER CONSTRUCTIONApplication filed amt i5, 1927, Serial My invention relates to' boilersof the socalled flash type, and it has particular relation to the classof flash boilers which are my ployed in automobiles. The present appli-5 cation is a continuation in part of my copending application, SerialNumber 654,7 51, filed July 30, 1923.

One of the objects of the invention is to provide a flash boiler whichwill supply steam 1 0 to the engine that is practically'free ofentrained water, regardless of how suddenly a load may happen to havebeen applied to the boiler.

Another object of'the invention is to provide a boiler in which thedisengagement of steam and water is substantially completelyetlectuated. k

A further object of the invention is to pro- ,vide a throttle controlsystem for superheated steam, whereby the throttle valve is f notexposed to the destructiveelevated temperature of super-heated steam.

Another object of the invention is to devise a water drum in which thewater is at all times in a state "of violent agitation.

It is a further object of this invention to arrange the heating elementsof the boiler, whereby the circulation of water therethrough is improvedand the possibility of $0 reversal in circulation, due to instantaneousheating, is minimized.

The present'invention also has as an object the provision of .a novelwater drum which requires comparatively little fabrication, and whichmay be constructed at a material savingin cost over that of the waterdrums, now commonly employed.

Another object oi-this invention is to provide a steam coil which isparticularly adapted to undergo thermal expansion and contractionwithout impairing the quality of the joint between the coil and thedrum.

These together with other objects will be come. more apparent from aconsideration of the accompanying illustration of an embodiment of aboiler, which may be preferred together with a detailed description ofits 7 construction; to The figure is a s ectional elevational view 250.175,474. Renewed October 10, 1980.

Y Another feature of the present invention,

which is likewise aimed to improve the circulation of the water throughthe tubes, resides 0B in the particular combination and arrangement ofthe'water drum, the steam disengagement drum, and the water return pipe,together with the manner in which the steam and water is discharged inthe steam disenit gagement drum. According to therinvention, the waterreturn pipes or downcomers are shieldedv from direct exposure to theflame or combustion gases. This insures the continued downward movementof the water m which is separated in the steam disengage- I ment drumand returned to the water drum byway of the downcomers. Check valves inthe downcomersai'd in maintainin the desired direction of flow ofwaterin t e boiler. Heretofore, considerable difiiculty has been experiencedin providing a throttle valve which will withstand, successfully, theelevated temperatures of the super-heated steam v passing therethrough.This is due largely to the fact that the throttle valve is opened andclosed --frequently, while the vehicle is being operated inorder ,toaccelerate the same positively or negatively, as the driver may desire.According to this invention, a tWO- W stage super-heater is provided"between the stages of which the throttle valve is interposed. The firststage serves to dry the steam thoroughly1 and impart an initialsuperheat thereto, w ereas th second-stage increases the super-heat tohe extent desired.

The-boilerconsists of a housing 10, constructed preferably to include asuitable heat insulating material 11. The housing encloses a steamdrum-12 located in the upper portion thereof, a water drum or dome13,10:

vcated in the lower portion and a mass of coils and tubes 14 interposed.therebetween.

, The water drum or chamber consists of two annular adjoining steelpipes 16 and 17 which may be welded together and which areinterconnected by small tubes 18 to establish communicationtherebetween. Feed water is supplied to the water drumthrough a' feedwater preheater coil 19 which is disposed adjacent the housing 10, andwhich discharges the preheated water into the lower steel pipe 16. Aburner 21, of any desired construction for example, such asjsillustrated in my copatented June 18, 1929, Patent No. 1,717,667

is located within and slightly below the annular water drum. The flamefrom the 3; burner as well as the products of combustion,

rise and inter-mingle with a plurality of the water drum with the steamdisengaging drum. 7 It will be 'observed that each coil includes ahelical construction in which the convolutions, are of progressivelyincreasing diameter as they approach'the upper drum 12. It will alsobeobserved that the coil is at all points. inclined upwardly. Further-;-.more, the space allowed for the passage. of

gas is greater among the outer convolutions than among the lnnerconvolutions; this results in greater exposure to heat near the outorportion than near the inner portion of each coil, and assures a morerapid circulation of water through the coils. The steam drum 12 includesa plurality of flues 23 through which the combustion gases pass to adome. portion 24 of the furnace and finally to a discharglng passage orchimney 26. For the purpose of providing greater flexibility'andelasticity in the coil and also to insure a better and more secure jointbetween the coil and the steam drum, the upper ends of the individualcoils arepassed upwardly through e the 'flues of the steam dru'm andenter t drum from the'top.

V The end of each coil within the steam drum is curved slightly, inorder to discharge'the waterand steam tangentially and imparta whirlingmotion thereto. This construction affords a substantially completeseparationof steam from water inasmuch. as the watertends to accumulatenear the perimetrical portion of the steam drum, whereas the steam is,withdrawn from the drum through a centrally located tube 27 havingaperforated upper end. As the water isdischarged "from coils 22, itaccumulates near the outerportion of, the drum and flows into aplurality of downcomers 28 which interconnect the steam drum and thewater drum, and which are'interposed between the preheater coil and thewall of the boiler. A check valve 29- is com nected to the end of eachdowncomer within the water drum, in order to prevent a. re-'- pendingapplication Serial Number 126,305,

steam generating coils 22 which interconnect versal of flow of thewater. Suchh. reversal in flow would often otherwise result when heaterincludes two stages, the initial stage t of heating being brought aboutin a coil 30 which is disposed immediately above the steam generatingcoils 22, and which serves to dry the steam as well as to impart a lowdegree of superheat thereto, whereas the final stage of heating iseffectuated in a second coil 31 disposed within the annulus of the waterdrum. Between the two super-heater coils, a throttle mechanism 32 isinterposed for controlling the flow of steam from the boiler to theengine.

It will be understood, of course, that the invention is not limited to athrottle valve of any particular construction. It willlikewisebeunderstood that the check valves 29 employed, may be of anysuitable construc tion such for example as a flap valve. V

A boiler constructed according to the principles hereinabove set forthis relatively free from theshortcomings which have characterized flashboilers that have been utilized heretofore. For example, when theconsumption of steam is increased suddenly, and it is necer,comparatively no difficulties are experienced which flow from theentrainment of I lJJ essary to acceleratethe operation of the burnwaterin the steam supply. Accordingly, the

boileris very economical from the standpoint of water consumption, acharacteristic which is particularly desirable. Furthermore,a1reversalin the normal direction. of

flow-of water through the steamgenerating coils is practically obviated.Another advanta e of the boiler resides in the fact that a thrott evalve interposed in the manner sug-' gested is not exposed to thedestructive action of the highly super-heated steam. Gonse quently,frequent replacement of throttle valves is unnecessary.

Although I have illustrated and described but a single embodiment of theprinciplesof myrinventio'n, it will be apparent to those skilled in theart'that the invention issusceptible to many modifications withoutdeparting from the spirit thereof, and I desire,

therefore, that it be limited to accord only with the prior art in theappended claims; Having'thusdescribed my invention what .I-c laim anddesire to secure by Letters Patent 1. in a flash boiler, the combinationof a water drum consisting of an annular endless tube disposed adjacenta burner; a steam tion of the steam drum; a check valve in eachdisengaging drum above the water drum; return water pipes interposedbetween the water drum and the lower perimetrical porof said waterpipes; steam generating coils above the burner interconnecting the waterdrum and the steam drum, the convolutions of the individual coils beingof greater diameter as they approach the steam drum;

and vfeed water heating coils interposed between the return water pipesand the steam generating coils.

2. In a flash boiler, the combination of a water drum consisting of anannular endless tube disposed adjacent a burner; a steam disengagingdrum above the water drum; re-

turn water pipes each provided with a check valve interposed between theWater drum and the lower perimetrical portion of the steam drum; steamgenerating coils above the burner interconnecting the water drum and thesteam drum; means for shielding the return water pipes from exposuretothe hot boiler gases; and a two-stage superheater consisting of twocoils having a throttle valve disposed therebetween.

3. In a flashiboiler, the combination of a water drum consisting of anannular endless tube disposed adjacent a burner; a steam disengagingdrum above the water drum; return Water pipes each provided with a checkvalve interposed between the water drum and the lower perimetricalportion of the steam drum; steam generating coils above the burnerinterconnecting the water drum and the steam drum, the convolutions ofthe individual coils being of greater diameter as they approach thesteam drum; feed water heating coils interposed between the return waterpipes-and the steam generating coils; and a two-stage superheaterconsisting of two coils having a throttle valve interposed therebetween.

4. In a flash boiler, the combination of a water drum;'a steamdisengagement drum; water return tubes interconnecting the water drumwith the base of the steam drum; steam generating tubes likewiseinterconnecting the drums, said steam generating tubes being adapted todischarge the steam tangentially within the steam drum; a steam pipedisposed in the mid-portion of the steam drum for withdrawingsteamtherefrom; and a twostage superheater connected to said steam pipehaving a throttle valve interposed between the stages of thesuperheater.

5. In a flash boiler, the combination of a water drum; a steamdisengagement drum; water return tubes interconnecting the water drumwith the lower perimetrical portion of the steam drum; steam generatingtubes likewise interconnecting the drums,said generating tubes beingadapted to discharge steam tangentially within the steam drum; a steamdischarge pipe connected to the mid-portion of the steam drum; andasuperheater'connected to said steam discharge pipe, the saidsuperheater including a heatin tube for subjectin the steam to an initiasuperheat; a secon superheating tube subjecting the steam to a finalsuperheat; and a throttle valve for controllin the exit of steamdisposed between the initlal and final superheater tubes.

6. In a flash boiler, the combination of a water drum; a steamdisengagement drum; water returntubes interconnecting the-water drumwith the lower perimetrical portion of the steam drum, each tube beingprovided with a check valve; steam generating tubes likewiseinterconnecting the drums, said generating tubes being adapted todischarge steam tangentially within the steamdrum; a steam dischargepipe connected to the midportion ofthe steam drum; a multiple-stagesuperheater connected to the said discharge pipe, said superheaterincluding a heating tube for subjecting the steam to a low initial stageor controlling the exit of steam from the boiler.

- 7. In a flash boiler, the combination of a water drum; a steamdisengagement drum; water return tubes interconnecting the Water drumwith the' lower perimetrical portion of the steam drum; steam generatingtubes likewise interconnecting the drums, said generatingtubes beingadapted to discharge steam tangentially within the steam drum; a steamdischarge pipe for supplying steam to an engine, said pipe beingpositioned in the central portion of the steam drum; a feed water heaterconsisting of coils interposed between the water return tubes and thesteam generating tubes; a steam discharge pipe connectedto themid-portion of the steamdrum; a multilow initial superheat and athrottle valve,

located at the outside of the boiler so as not to be exposed to the heatthereof, between the initial superheating stage and the next super-,heating stage for controlling the exit of steam from the boiler.

' 8. In a device of the character described, an

open fire box; achamber surrounding the same; a preheating coil' mountedto enclose a space above the fire box and communicating with the chamberfor delivering water thereinto; a steam dome mounted above the spaceformed to allow the products of combustion to pass therethrough; asecondcoil mounted within the said space communicating with the chamber anddischarging into the steam dome means for drawing ofl steam fromsthesaid steam dome; an initial superheater coil connected tothe saiddrawing ofi bustion ass therethrough, a series of col means, saidsup'erheater coil being located adacent the said steam dome; a secondsuperheater coil within the said fire box located so as to be exposed tothe heat of the products of combustion before being cooled by contactbustion to pass and a downcomer leading the steam dome,

the chamber outside from the steamdome to of the preheating coil whichserves as a heatbarrier between the firebox and the downcomer.

10. In a device of the character described,-

an open fire box, a chamber surrounding the same, a preheating coilmounted to enclose the space above the fire box and communicating withthe-chamber'for delivering water thereinto, a steam dome mounted abovethe space having flue tubes to allow the products of combustion 'to'pass therethrough a series of coils mounted within the space a ve thefire box communicating with the chamber passing through the flue tubesand discharging into the steam dome tangentially whereb the steam isforced centerwise, and drain pipes for returnin the water from the steamdome to the said c amber.

' 11. In a device of the character described,

an open fire same, a preheating coil mounted to enclose the space I ingwith the chamber for dehvering water thereinto, a steam dome mountedabove the said space formed to allow the products cf combustion to passtherethrough from-said space, a series of coils mounted within the saidspace and communicatin with the chamber and the steam dome, an

osed at the outside of'the preheating coil or returning the water fromthe steam dome to the chamber whereby the dram pipes are protected fromextreme heat.

- 12. In a device of the character described, an openfire box, a chambersurrounding the same, a preheating coil mounted to enclose aspace abovethe fire box and communicatingwith the chamber for delivering waterthereinto, a steam dome mounted above the space formed to allow theproducts of commounted within the space abovethe fire box communicating,with the chamber and as.

- therethrough, a second coil mounted. within the said space communicatj3 ing with the chamber and discharging into box a chamber surroundingthe above the fire box and communicatdrain pipesdischarging into thesteam dome tangentially whereby the steam is forced centerwise, and a suerheating coil in the space above the fire ox having one'perforated endextending into the center of the steam dome for receiving the steam.

13. In a device of the character described,

a fire pot water chamber, a steam and water dome, a plurah-ty of steamgenerating coils communicating with the chamber *andthe dome, aplurality of steam generating coils communicating with the chamber andthe dome, said coils discharging tangentially against the s des; of thedome, for separating the water and steam, downcomers located inproximityto said sides for leading the se arated water to said chamber, andmeans'or protectin the downcomers against excessive heat in the fire ot.

dome, shid coils discharging against the sides ofthe dome for separatingthe water'and 15. In a device -0 the chai acter described,

a fire pot water chamber, a steam and water dome',-flue passages throughthe dome, a p lu rality of steam generating coils communicating withthechamber and the dome-and passing upwardly through theflue passages anddownwardly into the dome in oximityto the sides of the dome, said coilsdischarging against the sides, andi downcomers locate in proximity tothe sides for leading the sep- .arated water to said chamber.

'16. In a flash boiler, the combination of a water drum, a steamdisengagement drum, water return tubes interconnecting the water drumwith the lower perimetrical portion of the steam drum, steam generatingtubes-interconnecting the drums, said generating tubes having their'endsdisposed so as to dis- 1 charge [steam "within the steam drum, a steamdischarge pipe for supplying steam to an engine, said pi e beingpositionedin the central portiono the steam druin, and a feed waterheater consisting of coils interposed between the water return tubes andthe steam generating tubes. Y 17. In a flash boiler,"the combinaticn ofa water drum, a steam disengagement drum, water return tubesinterconnectin the water drum withthe lower perimetrica portion ofthes'team drum, each tube being provided with a check valve, a feedwater preheater coil so disposed as, to protect the water in the returnpipe from direct exp sure to the combustion gases employed for thepurpose'of generating the steam, steam generatingtubes ls likewiseinterconnecting thedrum s, said gene erating tubes having their endsdisposed so as to discharge steam tangentially w thin.

its

the steam drum, and a steam discharge pipe tapped into the midortion ofthe drum.

18. ha device oft e character described, an open fire box, a chambersurrounding the same, a preheating coil mounted to enclose a space abovethe fire box and communicating with the chamber for delivering waterthereinto, a steam dome mounted above the space formed to allow theproducts of combustion to pass therethrough, a plurality of conicalcoils mounted in overlying relation in the said space communicating withthe chamber and discharging into the steam dome, and a downcomer withinthe fire box leading from the steam. dome to the chamber, said downcomerbeing protected against excessive heat in the fire box by said preheatingcoil.

19. In. a device of the character described, an open fire box, a chambersurrounding the same, a steam'dome mounted above the fire box formed toallow theproducts of communicatinfi bustion to pass therethroughfalurality of coils in the space between the re box and steam dome andincluding a preheating coil surrounding the space between the fire boxand the dome and communicating with the chamber to deliver waterthereto, and a second coil communicating with the chamber anddischarging into the steam dome, and a downcomer leading from the steamdome to the chamber outside of said water preheating coil, saidcoilprotecting the 'downcomer against excessive heat in the fire box.

20. In a device of the character described, a combustion space, achambersurrounding the same, a preheating water container in heat conductingrelationship to the combustion space and communicating with the chamberfor delivering water thereinto, a steam dome, a second water containerin heat conducting relationship to saidspace and comwith said'chamberand discharging into t e steam dome, and a downcomer protectedagainstthe heat of said space by said preheating water container."

In testimony whereof, I aifix my signature.

FRANK J. CURRAN.

